Research progress in antineutrophil cytoplasmtic antibody associated small vessel vasculitis due to propylthiouracil

Abstract

Antineutrophil cytoplasmic antibody (ANCA) associated small vessel vasculitis (AAV) induced by propylthiouracil (PTU) accounted for 80%-90% of vasculitis due to anti hyperthyroidism drugs. AAV is the disease which involved the systems of respiration, kidney, skin, muscle, nerve, stomach and intestine and ophthalmology and otorhinolaryngology. The clinical manifestations of AAV include fever, weakness, weight loss, myalgia and arthralgia, purpuric skin injury, hematuresis, conjunctivitis, pulmonary alveolar hemorrhage, and acute renal failure, can be even life-threatening. Laboratory examination showed positive ANCA. The mechanism of AAV induced by PTU may be related to interaction of PTU and myeloperoxidase (MPO). Long-term use of PTU may be the high risk factor in AAV. Serum anti-MPO antibody positive, anti-MPO antibody titer and the affinity to MPO antibody may be also related to PTU-AAV. The diagnostic code of PTU-AAV include (1) appearance of clinical symptoms of small vessel vasculitis and have the specific relationship between symptoms and medication time; (2) ANCA test show positive or titer elevating; (3) tissue biopsy shows inflammatory reaction and necrosis in small vessels, and renal needle biopsy shows focal segmental necrosis of cellulose and /or crescentic glomerulonephritis; (4) other diseases which may induce vasculitis, such as infection and tumor can be excluded. The main treatments for AAV are withdrawal of PTU timely and rational combination of steroids and cytotoxic drugs. The prognosis of PTU-AAV is closely related to the damage range in small vessels. The overall prognosis of PTU-AAV is better than that of primary small vessel vasculitis. Key words: Propylthiouracil; Anti-neutrophil cytoplasmic antibody-associated vasculitis